Sunesis Pharmaceuticals, Inc. (NASDAQ:SNSS) announced the presentation of updated results from an ongoing Phase 1b/2University of Texas MD Anderson Cancer Center-sponsored trial of vosaroxin in combination with decitabine in older patients with previously untreated acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS). The results were presented Saturday in an oral session titled “New Compounds in AML Treatment” at the 21st Congress of the European Hematology Association (EHA) in Copenhagen, Denmark.
“Older patients diagnosed with AML and MDS have limited treatment options and exceedingly poor outcomes,” said Naval Daver, M.D., Assistant Professor, Department of Leukemia, University of Texas MD Anderson Cancer Center, and a study investigator. “At the optimized induction dose of 70 mg/m2of vosaroxin, the combination of vosaroxin and decitabine demonstrates a compelling CR/CRp/CRi rate of 76% and a median overall survival of 16.1 months. This response rate and survival are significantly better than seen with single-agent decitabine among similar patients at our institution. This outcome was achieved with <5% induction mortality and good tolerability. In this vosaroxin-decitabine cohort, 23 of 41 patients remain alive.”
Daniel Swisher, CEO of Sunesis, added: “We believe these results warrant further exploration in a larger outcome study, with plans currently under review to conduct a multicenter clinical trial comparing vosaroxin plus decitabine and vosaroxin plus cytarabine to the 7+3 regimen in patients with AML.”
To date, 63 patients (56 AML, 7 high-risk MDS) with a median age of 69 years (range 60-78) have been enrolled in the trial. All 63 patients have completed at least 2 treatment rounds, rendering them evaluable for response; with a 75% overall response rate, 49% (31 patients) achieved complete remission (CR), 17% (11 patients) achieved CR with incomplete platelet recovery (CRp), and 8% (5 patients) achieved CR with incomplete peripheral blood count recovery (CRi). The therapy was well-tolerated, with the main therapy related grade 3 or higher toxicities being mucositis in 11 (17%) patients.
Initially for the first 22 patients in the study, the selected induction dose of vosaroxin was 90 mg/m2. Thereafter to reduce the incidence of mucositis, the induction dose was reduced to 70 mg/m2 for the next 41 patients. The lower dose of vosaroxin in combination with decitabine was associated with reduced early mortality and an improved overall response rate and OS, as follows:
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Sunesis also announced that follow-up data from the company’s VALOR trial was presented as an e-poster during the EHA meeting. The poster (abstract E930, Bella Center, E-Poster Screens), titled “Characterization of patients with relapsed or refractory AML in continued follow-up after treatment with vosaroxin/cytarabine vs placebo/cytarabine in the VALOR trial,” shows that, as of January 22, 2016, 83 of 711 patients enrolled in VALOR remain alive (46/356 in the vosaroxin/cytarabine arm, 37/355 in the placebo/cytarabine arm) and in follow up, which has reached a median of 40 months. In patients ≥60 years, more than twice as many patients were alive in the vosaroxin/cytarabine arm (23 vs. 10 patients).
All but seven patients in this follow up underwent allogeneic hematopoietic stem cell transplant (HCT). Of note, the non-HCT survivors were all in the vosaroxin/cytarabine treatment arm (68-71 years old, 2 primary refractory and 5 early relapsed).
Mr. Swisher added: “We are encouraged by the long-term benefit seen in the VALOR follow-up and also the potential for vosaroxin and cytarabine to provide long-term benefit in older patients who need more options.” (Original Source)
Shares of Sunesis are up over 18% to $0.645 in pre-market trading. SNSS has a 1-year high of $3.72 and a 1-year low of $0.44. The stock’s 50-day moving average is $0.51 and its 200-day moving average is $0.68.
On the ratings front, Cantor Fitzgerald analyst Mara Goldstein reiterated a Buy rating on SNSS, in a report issued on May 5. According to TipRanks.com, Goldstein has a yearly average return of -10.6%, a 35.2% success rate, and is ranked #3831 out of 3892 analysts.